3-12 



In addition to routine survey and post-survey calibrations, 

 beginning in July 1976 water samples were collected at Stations 2, 9 and 

 20 at surface and near bottom on each ebb-tide survey for independent 

 determination of salinity (by laboratory salinometer) and dissolved 

 oxygen (by Winkler titration) . These independent estimates were used as 

 a check on accuracy of the Hydrolab Surveyor. 



Continuous Monitoring Station 



A Honeywell continuous water quality monitoring station has 

 been in operation on the New Haven Harbor Station pier since August 

 1970. Water is pumped to the sensing instrument package from a depth of 

 12 ft below mean sea level (MSL) ; reported data refer to this depth 

 unless otherwise indicated. Except for gaps due to maintenance and 

 malfunctions, data have been recorded continuously at 6-min intervals 

 for the following parameters: 



Time Temperature (at surface and -12 ft 



pH MSL) 



Conductivity Tide height (diaphragm positioned at 



Turbidity -12 ft MSL) 



Dissolved Oxygen 



Accuracy of the various sensors was checked weekly against alternative 

 instruments or chemical analysis (dissolved oxygen) and appropriate 

 adjustments were made to the Honeywell unit accordingly. 



DESCRIPTION OF NEW HAVEN HARBOR HYDROGRAPHY 



In general, our surveys have shown that New Haven Harbor 

 experiences typical seasonal patterns in physical/chemical parameters: 

 1) warmest water temperatures are reached in July and August, while 

 coldest temperatures occur in January and February; 2) lowest salinities 



